In a standard butterfly exercise station a pair of upstanding padded wings are swing-mounted in elevated positions at opposite sides of a seat for hand and forearm engagement from the back side so that the wings can be swung forwardly by the exerciser in opposition to a weight stack or other load. Usually the load is connected to the wings by a cable system including a cable passing over a sheave and having its ends anchored to respective arched cams so that as the wings are swung forwardly during a butterfly exercise the cams are rotated thereby winding end sections of the cable partway onto the cams and pulling the sheave which is in turn interconnected with the weight stack. Such a system is disclosed in U.S. Pat. No. 4,809,972. In the past minor adjustment of the connection between the ends of the cable and the cams has been provided for by providing cable anchoring fittings on the cams which could be screw-mounted on the cams at selected mounting hole positions. Such an adjustment arrangement is inconvenient to use if the butterfly station is to be used frequently by different people desiring different adjustments.